From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Greear <greearb@candelatech.com>,
David Miller <davem@davemloft.net>,
netdev@vger.kernel.org, gregkh@linuxfoundation.org
Subject: Re: RCU lock bug in 3.0.21 (bisected to: 682cb56a, fix NULL dereferences in check_peer_redir)
Date: Mon, 26 Mar 2012 22:11:20 -0700 [thread overview]
Message-ID: <20120327051120.GM2450@linux.vnet.ibm.com> (raw)
In-Reply-To: <1332806834.3547.16.camel@edumazet-glaptop>
On Tue, Mar 27, 2012 at 02:07:14AM +0200, Eric Dumazet wrote:
> On Mon, 2012-03-26 at 16:46 -0700, Ben Greear wrote:
>
> > The 3.0.21 kernel doesn't appear to have a rcu_read_lock_return(),
> > so I can't use your patch below.
>
> This patch was only to show the point (I also CCed Paul, he might have
> some time to think about it, after he clears the inline stuff with
> Linus)
There is an rcu_preempt_depth() that returns rcu_read_lock() nesting
level for CONFIG_PREEMPT_RCU=y on the one hand and returns zero
for CONFIG_PREEMPT_RCU=n on the other. So if you can reproduce
with CONFIG_PREEMPT_RCU=y, you can substitute rcu_preempt_depth()
rcu_read_lock_return() in Eric's earlier patch.
Thanx, Paul
> As I said, I was referreing to you adding stuff in rcu. ;)
>
> Unfortunately I wont have time in the near future to do so myself.
>
>
>
next prev parent reply other threads:[~2012-03-27 5:11 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-26 21:43 RCU lock bug in 3.0.21 (bisected to: 682cb56a, fix NULL dereferences in check_peer_redir) Ben Greear
2012-03-26 21:49 ` David Miller
2012-03-26 21:53 ` Ben Greear
2012-03-26 23:06 ` Ben Greear
2012-03-26 23:11 ` David Miller
2012-03-26 23:39 ` Eric Dumazet
2012-03-26 23:46 ` Ben Greear
2012-03-26 23:53 ` Ben Greear
2012-03-27 0:07 ` Eric Dumazet
2012-03-27 5:11 ` Paul E. McKenney [this message]
2012-03-27 5:30 ` Ben Greear
2012-03-27 16:47 ` Paul E. McKenney
2012-03-27 16:47 ` Ben Greear
2012-03-27 18:06 ` Eric Dumazet
2012-03-27 19:39 ` Eric Dumazet
2012-03-27 19:53 ` [PATCH] net: fix a potential rcu_read_lock() imbalance in rt6_fill_node() Eric Dumazet
2012-03-27 20:07 ` Ben Greear
2012-03-27 20:17 ` Ben Greear
2012-03-27 20:25 ` Greg KH
2012-03-27 22:22 ` David Miller
2012-03-28 0:54 ` John Fastabend
2012-03-28 1:27 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120327051120.GM2450@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=greearb@candelatech.com \
--cc=gregkh@linuxfoundation.org \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).